Annular subvalvular left ventricular aneurysm was first reported in 1962. This type of aneurysm usually arises from the annular subaortic or submitral region of the left ventricle. It should be differentiated from the left ventricular false aneurysm, which was caused by myocardial necrosis. The etiology of subvalvular aneurysm remains unclear. We have presented a case of annular submitral left ventricular aneurysm. The patient had no history of coronary artery disease. Two-dimensional echocardiography and magnetic resonance image (MRI) showed a huge left ventricular aneurysm existed. An annular submitral left ventricular aneurysm was confirmed by an open heart surgery and pathological examination.